1. Field of the Invention
Disclosed embodiments relate to a large-area probe card, and more particularly to a large-area probe card and a method of manufacturing the same, which can improve flatness of the probe card and solve problems relating to a connecting structure between contactors and a main substrate.
2. Description of the Related Art
A semiconductor device is typically manufactured through a fabrication process in which circuit patterns and contact pads for inspection of a circuit are formed on a wafer and an assembly process in which the wafer including the circuit patterns and the contact pads formed thereon are assembled into individual semiconductor chips.
Between the fabrication process and the assembly process, an inspection process is performed for inspecting electrical properties by applying an electrical signal to the contact pads formed on the wafer. The inspection process is intended to inspect defects of wafers and remove defective wafers during the assembly process.
In the inspection process, an inspection instrument for applying electrical signals to a wafer, which is called a tester, and another inspection instrument fulfilling a function of an interface between the wafer and the tester, which is called a probe card, are dominantly used. The probe card includes a printed circuit board for receiving electrical signals and a plurality of probes adapted to come into contact with contact pads formed on the wafer.
In recent years, with the increase in demands for highly integrated semiconductor chips, circuit patterns which are formed on the wafer through the fabrication process are highly integrated, thus resulting in a reduced pitch interval between adjacent contact pads.
In order to inspect contact pads having a fine pitch, probes of a probe card have to be configured to also have a fine pitch. Consequently, the so-called space transformer, which is designed to compensate for the difference between the spacing of terminals on a printed circuit board and the spacing of probes, is provided between the printed circuit board and the probes.
A conventional probe card includes a printed circuit board, an interposer, a space transformer and probes. The printed circuit board includes probe circuit patterns which are formed for the inspection process, and function to receive electrical signals applied from a tester and transfer the electrical signals to the probes.
The interposer is connected to the probe circuit patterns of the printed circuit board, and functions to electrically connect the probes to the printed circuit board.
The space transformer can fulfill a function of pitch transformation by virtue of the configuration in which a spacing (pitch) of first pads is smaller than a spacing (pitch) of second pads.
In this context, the space transformer is made of a multi-layer ceramic (MLC), and transfers electrical signals, which are received from a printed circuit board, to probes through a conductive layer formed therein.
The multi-layer ceramic substrate is manufactured by alternately forming conductive layers and insulation layers on an insulation substrate multiple times. However, because the conventional space transformer is manufactured by alternately overlapping conductive layers and insulation layers multiple times, it results in a long and complicated manufacturing process, thus increasing manufacturing costs.
A space transformer undergoes thermal expansion or contraction under high or low temperature test conditions, but a conventional probe card does not use an alignment device, thus a misalignment between a probe block containing probes and the space transformer occurs. Consequently, this causes incorrect results when testing the electrical properties of semiconductor devices.
Furthermore, in conventional cases, when the number of probe pins increases due to the reduction of the pitch of semiconductor devices, the total size of the probe card increases and thus the spatial conditions are constricted.